Conventional instrument devices of this type are provided with an analog meter, for example, and the analog meter is provided with a display board and a pointer. Scale marks and numbers corresponding to rotation of the pointer are formed on the display board. The display board is made of a translucent substrate and shielded from light by black printing except for portions used for display, such as the scale marks and letters. Transmission illumination by a light source provided behind the display board enables the scale marks and the letters to be displayed. A front face of the meter is provided with a half-transparent protection cover colored with a dark color. The protection cover protects the meter and reduces an incident amount of external light or an amount of internal light. Since the display light of the meter having high emission brightness is reduced by the protection cover, only the displays such as the scale marks and the letters and the pointer stand out in darkness to be displayed without showing inside of the protection cover (see, for example, JP 07-098235 A).
However, since only the displays such as the scale marks and the letters and the pointer stand out in darkness to be displayed in the conventional instrument device, the illumination of the display lacks in savor and novelty.
The present invention has been accomplished in view of the above-described circumstances, and an object thereof is to provide an instrument device capable of performing a novel illumination.